Incandescent and fluorescent light sources have been known to be the most popular sources of visible white light. However, these traditional light sources have been known to use electrical energy supplies and give off undesirable amounts of heat when being used.
The Secretary of Energy, Spencer Abraham, at the 13th Annual Energy Efficiency Forum (Jun. 12, 2002) referred to solid-state lighting as an “area of exciting possibilities.” He went on to say, “The time has come to take the next step toward solid state lighting” and he used the organic light-emitting diode (OLED) and the light-emitting diode (LED) as examples of solid-state lighting technologies. These devices utilize one of two approaches for generating visible white light. The first approach is to use the additive combination of several wavelengths generated by LEDs such as red, green, and blue to produce white light. The second is to use either ultra-violet (UV) or blue light from an LED to pump a phosphor material to down-convert the light to the visible spectrum, where careful selections of phosphors are required in order to yield white light.
In the solid-state lighting field LEDs and OLEDs are well known sources of providing white visible light for general illumination and as decorative light sources. The highest efficacy LED with the greatest luminous output is the LumiLeds 5 W Luxeon. This LED emits 120 lumens with a 5 W electrical input or 24 lumens/watt. This LED has been in development for 5 years and has had the benefit of millions of dollars of development as general illumination and decorative light sources.
U.S. Pat. No. 6,327,074 to Bass et al., by the same assignee, the University of Central Florida, as the subject invention, describes the use of upconversion materials that can be used in a “Display medium using emitting particles dispersed in a transparent host”, where the display mediums are limited to two dimensional and three dimensional display devices. The generation of white light using upconversion materials encapsulated in p-PMMA is also described by the same assignee in a related application, U.S. Ser. No. 09/919,131 to Bass et al. filed Jul. 31, 2001, by the same assignee as that of the subject application and is also limited to being used only in display mediums such as two and three dimensional displays.
To the inventors knowledge, no one uses upconversion materials such as those disclosed in the patents and patent applications of the subject assignee for the generation of white light or colored lights as a visible light source that can be used in general illumination lights sources and/or for decorative light sources.